It is known to provide apparatus of the kind referred to and incorporating a heated furnace kiln through which the scrap material is passed, with circulation of hot gases through the kiln in a closed circuit for said vapourization or burning of contaminants. An example of such apparatus incorporating a rotary kiln is disclosed in U.S. Pat. No. 5,055,037, issued Oct. 8, 1991, the disclosure of which is incorporated by reference.
The object of the present invention is to provide heat processing apparatus for the above purpose, e.g. incorporating a rotary kiln, which is economical to manufacture and install, compact, adaptable in design, and effective and efficient in operation.